Geology

http://www.dlese.org/library/index.jsp

Earthquakes and Plate Tectonics

http://earthquake.usgs.gov/learning/topics/?topicID=62&topic=Field%2520trips%2520-%2520virtual,%2520real
http://www.pbs.org/wgbh/aso/tryit/tectonics/
http://volcano.und.nodak.edu/vwdocs/vwlessons/plate_tectonics/part1.html
http://www.platetectonics.com/book/page_6.asp
http://www.ucmp.berkeley.edu/geology/tectonics.html

Rocks and Minerals

Virtual Fieldtrips
Geology Explorer
Rocks and Minerals Slideshow
Rock Hounds
Rock Cycle Game
http://www.bbc.co.uk/schools/gcsebitesize/chemistry/changestoearthandatmosphere/0rocksrev1.shtml
Mineral Properties
Crystals
http://www.teachers.ash.org.au/jmresources/rocks/links.html